Automatic-manual change-over switch capable of providing pressure indication

ABSTRACT

In a manual operation, the ultimate pressure at an automatic operation is stored by the position of a pointer. When the pointer is set on any desired pressure position, the back pressure of a nozzle becomes the input pressure to a pilot valve to feedback the back pressure to a beam to balance the beam.

United States Patent 1151 3,698,247

Doki 1451 Oct. 17, 1972 [54] AUTOMATIC-MANUAL CHANGE- [56] References Cited OVER SWITCH CAPABLE OF UNITED STATES PATENTS PROVIDING PRESSURE INDICATION 2,061,118 11/1936 Vogt ..73/388 BN [72] inventor: Yoshikuni Doki, Tokyo, Japan Primary Examiner-Donald O. Woodiel [73] Asslgnee' gg Fort washmgton Attorney-Arthur H. Swanson and Lockwood D. Burton [22] Filed: June 9, 1971 21 Appl. 110.; 151,227 [57] ABSTRACT In a manual operation, the ultimate pressure at an automatic operation is stored by the position of a ..73/388 pointer when the pointer is set on y desired p g i 137/82 sure position, the back pressure of a nozzle becomes the input pressure to a pilot valve to feedback the back pressure to a beam to balance the beam.

1 Claim, 2 Drawing Figures sum 1 or 2 i INVENTOR YOSHlKUNI DOKI ATTORN EY PAIENTEDUBI 17 I972 SHEET 2 BF 2 INVENTOR YOSHIKUNI DOKI BY Z Z 2% Z;

ATTORNEY AUTOMATIC-MANUAL CHANGE-OVER SWITCH CAPABLE OF PROVIDING PRESSURE INDICATION BACKGROUND OF THE INVENTION This invention relates to an automatic-manual change-over device for a pneumatic controller capable of providing means for indicating a pressure.

SUMMARY OF THE INVENTION In this invention, a first pointer is provided for indicating an output pressure on a scale by rotating around a fulcrum following to the displacement of a first beam, and a second pointer is provided for manual setting, which, at an automatic state, follows the displacement of a second beam together with a first pointer and, at a manual state, indicates a set value.

It is an object of this invention to provide an automatic-manual change-over switch which can manually indicate a set value of an output pressure.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a circuit diagram for showing the principle of this invention, and

FIG. 2 is a perspective view of the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT The principleof this invention will now be explained with reference to FIG. 1, wherein a flow path 12 branched from an output 16 of a pilot valve 15 is led to bellows 55, which is restorable by means of a spring 56, and wherein a first beam 19 is mounted pivotally swingable around a fulcrum 59 between spring 56 and bellows 55, on bellows 55 is applied a back pressure P as an input thereto, an output pressure P of pilot valve 15 being impressed on bellows 55. On beam 19 is secured a nozzle 21 of a flexible tube 22, which is supplied either with the back pressure P from branched path 12 through a pneumatic switch 14 or with a supply pressure P, through a throttle R.,. A second beam 23 is disposed against nozzle 21 pivotally around a fulcrum 61 of a stand 60 provided at one end of first beam 19, the two beams being adapted to be enable to restore the original relative positions thereof. Second beam 23 is connected through a spring 47 with a pointed 41 swingable around a fulcrum 25 over a scale 43 and a rod 46 is protruding from pointer 41 under being adapted to abut beam 23 with tip end 57 of the rod. Similarly, first beam 19 is also connected through a spring 49 with another pointer 42 swingable around a fulcrum 50 over another scale 44 and a rod 48 is protruding from beam 19 under being adapted to abut pointer 42 with the tip end of the rod. Pointer 41 is swingable together with a disc frame 24 secured thereto, the disc being releaseably connected through a clutch 27 to a knob 26.

In the automatic operation with pneumatic switch 14 switched on to the A-side, pilot valve supplied with a pressure P,- will make the input pressure P into the output pressure P to apply it on bellows 55, and the output pressure is transmitted through first beam 19 to pointer 42 thereby to indicate the pressure amount on scale 44. On the other hand, nozzle 21 receiving the supply pressure P through the throttle R is made to close the mouth thereof by second beam 23 due to the biasing force of spring 62, whereby second beam 23 will follow to first beam 19 to move therewith, and accordingly pointer 41 will also follow to the second and first beams to swing over scale 43, clutch 27 being understood not to be engaged.

In the manual operation with pneumatic switch 14 switched on to the M-side, clutch 27 is adapted to be engaged through means not shown in the drawing, and a smooth changing-over may be accomplished, as the ultimate pressure at the automatic operation is stored by the position of pointer 41. Due to clutch 27 being on engaged state, pointer 41 may be set on any desired pressure position on the scale by rotating knob 26 after having been switched over to the manual state. In the above process, the back pressure of the nozzle will become the input pressure to pilot valve 15, the out-put pressure of which may be fed back to bellows 55 to make first beam 19 to be balanced.

FIG. 2 shows a structural arrangement embodically constituted according to the above principle, parts corresponding to those stated referring to FIG. 1 are designated by the same numbers as shown in FIG. 1. Those members as stated above are mounted on a base plate 10, a scale plate 45 serving a role of scale 44 as well as of scale 43 in unification of the both. Pointer 42 and pointer 41 for manual setting are swingable around a pivot 50, which has been unified with fulcrum 25 and is erected on the base plate. Pivot 50 is adapted to receive a coiled spring 47 for pointer 41 as well as a spring 49 for pointer 42, and the two pointers are adapted to swing such that pointer 41 will make a clockwise stroke (as seen in the drawing) and pointer 42 will make a counter clockwise stroke in their independent motions according to the returning actions of the respective springs. Pointer 42 is engaged with first beam 19 through the relation between an L-shaped plate attached to pointer 42 and a tip end 91 of an arm 48 protruding from beam 19, wherein means are adapted such that, if the beam moves rightwards due to an increase of the pressure within bellows 55, pointer 42 follows the displacement of the beam by aid of the restoring force of spring 49, but if the beam moves leftwards due to a decrease of the pressure within bellows 55, pointer 42 will accompany thereto.

Pointer 41 is attached to an are 31 of disc frame 24 swingable around pivot 50, and it will displace in accordance with the sector swinging to make movement of the tip of the pointer over scale 45. The tip end of pointer 41 is made smaller than that of pointer 42, the former may be hidden by the latter if the both happen to show the same scale position. The engagement between pointer 41 and second beam 23 is produced between bent end 57 of lied down U- or J-arm 40 erected on disc frame 24 and the right end portion of beam 23, and pointer 41 will follow the displacement of beam 23 as stated above. An inner are 32 of the arcuate side of sector frame 24 is provided with teeth, which are adapted to be releaseably meshed with a pinion 27 which is rotatably attached to an L-shaped lever 34 swingable around a fulcrum 33, and by turning lever 34 upwards the disc frame may be out of engagement with the pinion, and by turning the same in opposite direction there will be produced a reengagement. Another manner of engagement may be contemplated between pinion 27 and inner arc 32 without saying. A cable 37 is stretched between and over a pulley 35 fixed coaxially to pinion 27 and a pulley 36 fixed coaxially to a knob 26 rotatably mounted under base plate 10, cable 37 consisting of a coiled spring, so that if knob 26 is manually turned, the rotating motion will be transferred through members 36, 37 and 35 to pinion 27, and in manual state wherein pinion 27 and inner are are engaged, the position of pointer 41 may be set at any desired point by suitably rotating knob 26. Member 62 is a coil spring in FIG. 1 but the same reference number in FIG. 2 shows a leaf spring disposed between beams 19 and 23.

As the device is constituted as shown in FIG. 2, if it be operated together with pilot valve 15, pneumatic switch 14, etc. as shown in FIG. 1, it may operate according to the principle as illustrated by virtue of FIG. 1. In the manual state wherein lever 34 is brought to the position as seen in the drawing through means not shown to make pinion 27 to engage with sector frame 24, if knob 26 is turned to bring pointer 41 to a point to show the manually set pressure, an operation as stated above will take place to move pointer 42 up to the manually set position after a certain period of time, whereby the pointer will be covered to indicate that the manually set pressure is maintained. In the above operation, pointer 42 moves surely to show the position of pointer 41 stopping, so that manual setting of pressure may be done very easily.

I claim:

1. An automatic-manual change-over device for a pneumatic controller, which is bumplessly switchable from state of automatic to manual, said device comprised of a first beam (19) swingable around a fulcrum following the output pressure of a pilot valve and a second beam swingable around a fulcrum (61) provided on said first beam disposed against a nozzle (21), said nozzle being secured to said first beam and being adapted to displace together with said first beam, said nozzle being adapted to be applied with an input pressure directed to the pilot valve at manual state and with a supply pressure at automatic state, characterized by a pointer (42) for indicating the output pressure on the scale (44) by rotating around a fulcrum (50) following to the displacement of said first beam, and by an indicator for manual setting, which will follow, at automatic state, the displacement of the second beam to make an independent swing around said fulcrum to thereby make displacement over the scale substantially together with said pointer (42), while, at manual state, which will indicate the set value so as to operate with a desired manually set amount through a coupled movement of a manually settable dial mechanism (26, 27 and 24). 

1. An automatic-manual change-over device for a pneumatic controller, which is bumplessly switchable from state of automatic to manual, said device comprised of a first beam (19) swingable around a fulcrum following the output pressure of a pilot valve and a second beam swingable around a fulcrum (61) provided on said first beam disposed against a nozzle (21), said nozzle being secured to said first beam and being adapted to displace together with said first beam, said nozzle being adapted to be applied with an input pressure directed to the pilot valve at manual state and with a supply pressure at automatic state, characterized by a pointer (42) for indicating the output pressure on the scale (44) by rotating around a fulcrum (50) following to the displacement of said first beam, and by an indicator for manual setting, which will follow, at automatic state, the displacement of the second beam to make an independent swing around said fulcrum to thereby make displacement over the scale substantially together with said pointer (42), while, at manual state, which will indicate the set value so as to operate with a desired manually set amount through a coupled movement of a manually settable dial mechanism (26, 27 and 24). 